No heat at feet (1 Viewer)

[woodwateradv]

Bought a somewhat neglected ‘00 LX this summer. PO brought it up from the south, so undercarriage is fairly clean with minimal surface rust.

Supposedly T belt was done but I went ahead and replaced it myself along with new radiator. When draining the block, the driver side drain was clogged. I unscrewed the drain and stuck a small screw driver in there and out came the rust bits with water.

Flushed the block a few times then decided I should flush the heater core too. Didn’t find any rust bits from the core…or so I thought.

Got done reassembling rad, T belt, water pump, fan clutch, etc. and started to burp the cooling system. Full blast heat front and rear. Heat came out fairly nice until cooler weather when I noticed front wasn’t hot at all. Rear was piping hot. Front heat would get luke warm only if I turn on recirculating mode. When I set mode to max hot to face and feet, fresh air from outside, air from face vents is slightly warm and feet would get cool air.

Today I decided to flush the core again and found this:

With this out of the front core the front heat is a lot better than before but still not as hot as rear. Air to defrost and face with fresh and recirculating is “hot” but, still not getting heat to feet unless I select recirculating mode.

Any thoughts on how I should proceed with this?

Also, I plan to do a full cooling system flush this spring/summer. Is there any recommended chemical I should use? I would like to get most if not all the rust out of the cooling system.

Thanks in advance.

 

[Gnarwgn]

Following along...I have a similar issue - defrost, defrost+feet, feet only settings all do the same thing, which is only defrost. I can't get heat to my feet. Otherwise my heat is functional. Going to see if recirculation mode makes any difference but I suspect no.

Someone mentioned that the feet gates act on a vacuum, and suggested removing the stereo/hvac controls and panel, and get behind that to figure out what is going on. I have yet to take that step...

 

[Trunk Monkey]

If you have heat at the upper vents but not at the feet one of the most common causes reported here has been that the carpet has gotten pulled up over the floor vents on each side. If your upper vent doesn't get warm with the HVAC set to hot, then that's another issue - could be the diffuser, heater core issue

 

[Exiled]

There was a post in the last two weeks where a member had gone through a significant problem-solve of lingering AC issues and I remember one of the "aha" moments was the mechanical baffles/vents not working properly, and that when he disassembled and used dry lubricant on them he was able to resolve. Do a quick search, it might be something similar going on?

 

[Gnarwgn]

There was a post in the last two weeks where a member had gone through a significant problem-solve of lingering AC issues and I remember one of the "aha" moments was the mechanical baffles/vents not working properly, and that when he disassembled and used dry lubricant on them he was able to resolve. Do a quick search, it might be something similar going on?

Good recall - I think this is the one:

Heater problem finally solved (two years!)

Dear Mudders, My heat (or lack thereof) has been driving me to the point of wanting to sell my 100. For two years or so I have been battling extremely cold air through the floor vents, in some instances AC in winter, and moderate heat from the top vents. I finally fixed it through a succession...

forum.ih8mud.com

 

[Exiled]

Yes! Thanks, @Gnarwgn !!!

 

[woodwateradv]

If you have heat at the upper vents but not at the feet one of the most common causes reported here has been that the carpet has gotten pulled up over the floor vents on each side. If your upper vent doesn't get warm with the HVAC set to hot, then that's another issue - could be the diffuser, heater core issue

I have checked, passenger side carpet was blocking vent. Still no heat unless recirculate mode is on.

Things I’ve checked so far:
1: new thermostat and hoses when I did T belt, jiggle valve on top
2: burped cooling system, full of coolant
3: coolant temp 185 degrees at normal operating temp
4: passenger carpet was blocking foot vent, no longer blocked
5: air blend motor working if I am able to get “heat” everywhere else but foot? Confirmed moving when changing temp, no unusual noise from motor
6: cabin air temp hose was unplugged, cleaned the sensor and plugged hose back on (this is only used when auto climate control is used? I never use auto mode)

Still no heat to foot vents unless recirculating mode is on. Blows cool air on fresh air mode.

Good recall - I think this is the one:

Heater problem finally solved (two years!)

Dear Mudders, My heat (or lack thereof) has been driving me to the point of wanting to sell my 100. For two years or so I have been battling extremely cold air through the floor vents, in some instances AC in winter, and moderate heat from the top vents. I finally fixed it through a succession...

forum.ih8mud.com

I haven’t checked #5 yet on this post. Will have to take a look when/if temps warm up, otherwise will have to wait till spring/summer.

 

[Gnarwgn]

Ok here's an update of my slow crawl thru this situation:

1. floor carpet was covering the vents, so adjusted that. Went from nothing to 'whisper' level output.
2. unlike others - recirculation doesn't change the output on the floor vents, which remain at a 'whisper' level of output. Defrost, feet only, and defrost/feet settings continue to only function as defrost. No change in output direction when switching between the 3.
3. vent in steering column blows fine/as you would expect (not whiper)
4. vent coming out of back of console on floor to 2nd row blows fine/as you would expect (not whisper)

Can anyone confirm whether or not a servo is operating the gates for the floor vents? If so, I suspect that is my issue. If not, I suspect my gates are stuck closed, or whatever does operate the gates has ceased to function.

 

[woodwateradv]

@Gnarwgn sounds like air outlet servomotor and possibly stuck doors. If you go the the workshop manual and go under "repair manual" then “air conditioning” then "air outlet servomotor" you'll see that it controls where you direct the air. According to the FSM it is easier to replace than the air blend motor, which the whole dash has to come out. Outlet motor is located on driver side behind the cabin temp sensor.

Just to clarify, I am getting plenty of air to the feet, just not hot when fresh air mode is on. Which leads me to believe my air blend motor is weak.... And I don't want to pull my dash...

But I can see the air blend motor moving all the way when changing temp from cold to hot and vise versa… could be blend doors but I don’t hear any unusual noise… I am stumped